Showing papers in "IEEE Control Systems Magazine in 2011"
TL;DR: In this paper, orthogonal matrices are used to represent attitude in rigid-body rotational motion and to characterize attitude control systems for arbitrary attitude maneuvers without using attitude parameterizations.
Abstract: Rigid-body attitude control is motivated by aerospace applications that involve attitude maneuvers or attitude stabilization The set of attitudes of a rigid body is the set of 3 X 3 orthogonal matrices whose determinant is one This set is the configuration space of rigid-body attitude motion; however, this configuration space is not Euclidean Since the set of attitudes is not a Euclidean space, attitude control is typically studied using various attitude parameterizations Motivated by the desire to represent attitude both globally and uniquely in the analysis of rigid-body rotational motion, this article uses orthogonal matrices exclusively to represent attitude and to develop results on rigid-body attitude control An advantage of using orthogonal matrices is that these control results, which include open-loop attitude control maneuvers and stabilization using continuous feedback control, do not require reinterpretation on the set of attitudes viewed as orthogonal matrices The main objec tive of this article is to demonstrate how to characterize properties of attitude control systems for arbitrary attitude maneuvers without using attitude parameterizations
612 citations
TL;DR: In this paper, the authors present a panorama of analytical methods and computational algorithms using a unified eigenvalue-based approach illustrated by examples and applications in electrical and mechanical engineering, biology, and complex network analysis.
Abstract: Time-delays are important components of many dynamical systems that describe coupling or interconnection between dynamics, propagation, or transport phenomena in shared environments, in heredity, and in competition in population dynamics. This monograph addresses the problem of stability analysis and the stabilisation of dynamical systems subjected to time-delays. It presents a wide and self-contained panorama of analytical methods and computational algorithms using a unified eigenvalue-based approach illustrated by examples and applications in electrical and mechanical engineering, biology, and complex network analysis.
569 citations
TL;DR: In this paper, the authors describe the technical challenges in the wind industry relating to control engineering, and present an overview of the main challenges of wind energy control and its application in the control engineering field.
Abstract: Wind energy is a fast-growing interdisciplinary field that encompasses multiple branches of engineering and science. Despite the growth in the installed capacity of wind turbines in recent years, larger wind turbines have energy capture and economic advantages, the typical size of utility scale wind turbines has grown by two orders of magnitude. Since modern wind turbines are large, flexible structures operating in uncertain environments, advanced control technology can improve their performance.The goal of this article is to describe the technical challenges in the wind industry relating to control engineering.
407 citations
TL;DR: In this article, the authors proposed receding horizon control (RHC) as a straightforward method for designing feedback controllers that deliver good performance while respecting complex constraints, such as the objective, constraints, prediction method, and horizon.
Abstract: In this article we have shown that receding horizon control offers a straightforward method for designing feedback controllers that deliver good performance while respecting complex constraints. A designer specifies the RHC controller by specifying the objective, constraints, prediction method, and horizon, each of which has a natural choice suggested directly by the application. In more traditional approaches, such as PID control, a designer tunes the controller coefficients, often using trial and error, to handle the objectives and constraints indirectly. In contrast, RHC con trollers can often obtain good performance with little tuning. In addition to the straightforward design process, we have seen that RHC controllers can be implemented in real time at kilohertz sampling rates. These speeds are useful for both real-time implementation of the controller as well as rapid Monte Carlo simulation for design and testing purposes. Thus, receding horizon control can no longer be considered a slow, computationally intensive policy. Indeed, RHC can be applied to a wide range of control problems, including applications involving fast dynamics.
379 citations
TL;DR: In this article, the basic optical principles in the lithographic tool, with the resulting positioning accuracy requirements, are described, and the six degrees of freedom (DOF) stage control is described with the main focus on actuator force decoupling, allowing the use of classical SISO controllers.
Abstract: This article describes the basic optical principles in the lithographic tool, with the resulting positioning accuracy requirements. For three generations of lithographic tools, the mechatronic architecture and control implications are discussed. Then, six degrees of freedom (DOF) stage control is described with the main focus on actuator force decoupling, allowing the use of classical single-input, single-output (SISO) controllers.
289 citations
TL;DR: In this paper, the development of L1 adaptive-control theory and its application to safety critical flight control system (FCS) development is presented, and several architectures of the theory and benchmark examples are analyzed.
Abstract: This article presents the development of L1 adaptive-control theory and its application to safety critical flight control system (FCS) development. Several architectures of the theory and benchmark examples are analyzed. The key feature of L1 adaptive-control architectures is the decoupling of estimation and control, which enables the use of arbitrarily fast estimation rates without sacrificing robustness. Rohrs's example and the two-cart system are used as benchmark problems for illustration. NASA's flight tests on subscale commercial jet verify the theoretical claims in a set of safety-critical test flights.
177 citations
TL;DR: In this article, the authors provide an overview of the circle criterion and its connection with the ISS, which is concerned with the analysis of a feedback interconnection of Lure type, which consists of a linear system in the forward path and a sector bounded nonlinearity in the negative feedback path.
Abstract: This article provides an overview of the circle criterion and its connection with ISS. Classical absolute stability theory and the circle criterion in particular, is concerned with the analysis of a feedback interconnection of Lure type, which consists of a linear system in the forward path and a sector-bounded nonlinearity in the negative feedback path. Classical absolute stability results are revis ited in the context of systems described by differential inclusions and within a framework based on the complex Aizerman conjecture. Contrast with the classical literature that is focused mainly on asymptotic stability of the feedback interconnection, ISS issues are addressed and resolved.
79 citations
TL;DR: The Cornell biped as mentioned in this paper is a bipedal robot that is designed to be highly energy efficient and has the speed, stability, agility, and energy efficiency of a human. But it is difficult to construct.
Abstract: Research in bipedal robotics aims to design machines with the speed, stability, agility, and energetic efficiency of a human. While no machine built today realizes the union of these attributes, several robots demonstrate one or more of them. The Cornell biped is designed to be highly energy efficient.
70 citations
TL;DR: In this paper, a unifying classification of energy efficiency in terms of performance, operation, equipment, and technology (POET) is presented and then applied to heavy-haul train control problems.
Abstract: This article aims to provide an overview of the modeling and control of heavy-haul trains from an energy efficiency viewpoint. For this purpose, a unifying classification of energy efficiency in terms of performance, operation, equipment, and technology (POET) is presented and then applied to heavy-haul train control problems. A heavy-haul train is an energy system, and its cruise control can be viewed as an energy-efficiency control under this classification of energy-efficiency components. As shown in this article, heavy-haul train control technologies can be included in POET-based energy-efficiency control for operational performance improvement of a heavy-haul train.
39 citations
TL;DR: The IEEE Control Systems Magazine as mentioned in this paper asked Ted Brekken, Belinda Batten, and Ean Amon to respond to a query on the uses of systems and control technology in wave-energy production.
Abstract: In this issue of IEEE Control Systems Magazine we ask Ted Brekken, Belinda Batten, and Ean Amon to respond to a query on the uses of systems and control technology in wave-energy production. Ted, Belinda, and Ean are all involved in wave energy projects at Oregon State University.
21 citations
TL;DR: In this paper, the authors propose a control law that can safely return the vehicle to the ground after inadvertent tip-up of two wheels in the air by using active control.
Abstract: Cars and trucks are susceptible to accidents due to rollover. In the United States in 2005, 21.1% of a total of 54,718 deaths in vehicle crashes were caused by rollover [1]. Significant research has therefore been de voted to detecting and preventing rollover through active control. Numerous approaches attempt to detect or pre dict wheel liftoff using onboard sensing and a combina tion of automatic steering and braking to keep the wheels on the ground [2]-[4]. Rather than focusing on how to keep the wheels on the ground, it is also useful to under stand how to control a vehicle while two wheels are in the air. This understanding may enable the design of control laws that can safely return the vehicle to the ground after inadvertent tip-up.
TL;DR: In this paper, a closed-right-half-plane (CRHP) zero is shown to attract closed-loop poles, which limits the controller gain and thus the performance of the closed loop system.
Abstract: Nonminimum-phase zeros, that is, closed-right-half-plane (CRHP) zeros, affect both the open-and closed-loop behavior of continuous-time linear systems in undesirable ways [1]. For example, an asymptotically stable linear system with an odd number of positive zeros experiences initial undershoot to a step input (see “Initial Undershoot”). Moreover, under the rules of root locus, zeros in the open-right-half plane (ORHP) attract closed-loop poles, which limits the controller gain and thus the performance of the closed-loop system.
TL;DR: This paper found that the interest in science, technology, engineering, and mathematics (STEM) subjects continues to decline among K-12 students in the United States, and to foster excitement for STEM subjects among K -12 students, outreach and informal education programs often aim to infuse STEM fields with the energy typically reserved for activities such as sports competitions.
Abstract: As the need for science, technology, engineering, and mathematics (STEM) professionals grows in the United States, the interest of students in STEM disciplines continues to decline [1]–[3]. To foster excitement for STEM subjects among K–12 students, outreach and informal education programs often aim to infuse STEM fields with the energy typically reserved for activities such as sports competitions [4].
TL;DR: This article outlines a structure where the process of bubble formation is modeled as a nonlinear dynamic model and then used to design a state estimator and model-based predictor and Procedures are then calculated using explicit MPC.
Abstract: Decompression modeling of divers is a research field that is over 100 years old and since the beginning has been studied mainly as a clinical and biomedical problem. The topic is largely unexplored by the technological sciences using methods and theories for modeling and control. This article outlines a structure where the process of bubble formation is modeled as a nonlinear dynamic model and then used to design a state estimator and model-based predictor. Procedures are then calculated using explicit MPC. We further discussed dive-computer implementations using approximate explicit solutions. Finally, we showed practical differences for divers using computers that implement this approach. When future advances in sensor technology are made, the present structure can be further developed to include more feedback control of the estimator and optimal control formulation.
TL;DR: In this article, the authors describe a new method known as L1 adaptive control for bringing linear system design methods into adaptive control to confront several open problems, including the selection and tuning of adaptation gains, guaranteed transient performance of both states and controls, and guaranteed robustness margins.
Abstract: The book describes a new method known as L1 adaptive control for bringing linear system design methods into adaptive control to confront several open problems, including the selection and tuning of adaptation gains, guaranteed transient performance of both states and controls, and guaranteed robustness margins. Fast adaptation to allow aggressive maneuvering and recovery from failures is also confronted. A second key feature in L1 adaptive control is the use of a state-prediction system, whose dynamics can be prescribed and provide the reference model to be followed when the tracking and estimation errors are small. The third feature is the tuning of parameter estimates using projection methods. The block diagram of the resulting closed-loop adaptive system consists of linear components that can be analyzed using a mixture of linear frequency response techniques and adaptive control techniques.
TL;DR: One of the most impressive single displays at the 1984 International Machine Tool Show in Chicago was by a Japanese machine tool company, one of the largest producers of automated machine tools in the world.
Abstract: At the 1984 International Machine Tool Show in Chicago, where machine tool vendors from throughout the world bring their wares for display, one of the most impressive single displays was by a Japanese machine tool company, one of the largest producers of automated machine tools in the world. I was particularly impressed by an automatic tool changer on one of the company's machining centers, which is an automated milling machine that is at the core of small-batch production. This tool changer was a modular system capable of changing up to 700 tools.
TL;DR: In this issue of IEEE Control Systems Magazine, the paper as discussed by the authors answers a query on active flow control and provides a detailed discussion of active flow flow control in the IEEE 802.15.1 standard.
Abstract: In this issue of IEEE Control Systems Magazine, the paper answer a query on active flow control.
TL;DR: The style of the book is simplistic, sacrificing rigor for accessibility, which is appropriate for the intended readership, and it should satisfy the reader who wants to become familiar with the gist of what optimal control theory is all about.
Abstract: This 144-page book offers a concise introduction to optimal control theory and differential games, from the minimum principle (MP) to Hamilton-Jacobi-Bellman (HJB) theory. The book is based on lecture material developed by the author for a one- semester senior-year undergraduate or a fi rst-year graduate course, which he has taught at the Swiss Federal Institute of Technology at Zurich (ETHZ). The target audience of the book is practitioners in the field rather than academics or theoreticians working in the area of optimal control. To this end, the author does an excellent job of keeping the mathematical necessities to a minimum. The only prerequisites for the reader to follow the material in the book are system dynamics, state-space representations, and differential calculus. The author concentrates on three major topics, namely,the derivation of open-loop optimal controllers using MP,the conversion of optimal open-loop controls to optimal closed-loop controls, and the direct derivation of optimal feedback controls using HJB theory. In addition, in the final chapter the author offers a brief glimpse into the area of differential games. The style of the book is simplistic, sacrificing rigor for accessibility, which is appropriate for the intended readership. The book concentrates on the main ideas, leaving the details to a series of worked-out examples in each chapter. Overall, this works well, and it should satisfy the reader who wants to become familiar with the gist of what optimal control theory is all about.
TL;DR: The goal of the book is to explain in layperson¿s terms the essence of feedback and the basic tenets of the field of systems and control through prose and mathematics, through a wealth of multidisciplinary examples, and through block diagrams, graphs, photographs, and pictures.
Abstract: The goal of the book is to explain in layperson?s terms the essence of feedback and the basic tenets of the field of systems and control. The exposition aims at readers with a modest technical background. The relevant concepts are explained through prose and mathematics, through a wealth of multidisciplinary examples, and through block diagrams, graphs, photographs, and pictures. Each chapter begins with a humorous cartoon and one or two quotations. There are many footnotes, often with anecdotal tidbits about scientists figuring in the text and what these persons are famous for. The book is carefully edited with highlighted text to summarize the key points.
TL;DR: Most engineering is done offline, where the authors sit in quiet offices, work through problems over weeks and months, consult with coworkers, and eventually produce a solution.
Abstract: Most engineering is done offline. We sit in quiet offices, work through problems over weeks and months, consult with coworkers, and eventually produce a solution. Along the way, we propose and test ideas, correct errors, and refine designs. We stop at 5:00 p.m. and resume the next morning at 8:00 a.m., unless the weekend or vacation intervenes.
TL;DR: The Vice President of Membership Activities offers congratulations to the individuals who have been CSS members for 25 Years, listed here.
Abstract: The Vice President of Membership Activities offers congratulations to the individuals who have been CSS members for 25 Years, listed here.
TL;DR: The IEEE Control Systems Society (CSS) has a long history in the field of computer science and has been recognized as one of the most important organizations in computer science as mentioned in this paper. But what control is is a difficult question.
Abstract: I would like to start my series of president's messages by offering some personal reflections on what the IEEE Control Systems Society (CSS) can offer. To consider this question, I first want to take a diversion into what control is. Some time ago, as a junior faculty member, a colleague recommended I read the book What Is This Thing Called Science by A.F. Chalmers. It is a book on the philosophy of science that examines and critiques, in a form that I found quite accessible and entertaining, various views on the way in which science has developed and what it actually is. I won't claim to be able to match Chalmers' abilities, but I thought it would be interesting to examine a parallel theme and share some views on what control is.
TL;DR: In this article, de Callafon and Graham respond to a query on using sensors for a robotics application, and describe the use of such sensors in the field of control systems.
Abstract: In this issue of IEEE Control Systems Magazine, Raymond de Callafon and Gabe Graham respond to a query on using sensors for a robotics application.
TL;DR: The development of food recipes that are appetizing and nutritious is typically thought to be beyond the reach of science and engineering, but this goal challenging for numerical methods despite advances in computational power.
Abstract: The development of food recipes that are appetizing and nutritious is typically thought to be beyond the reach of science and engineering. In particular, chemistry and thermodynamics, not to mention sensory and aesthetic aspects, render this goal challenging for numerical methods despite advances in computational power.
TL;DR: The impact of control: overview, success stories, and research challenges as mentioned in this paper is a good starting point for our own research community and for society more generally, but it is not the only effort in looking at future directions for control, but does represent a substantial piece of work with input from many different people.
Abstract: A short while ago, the IEEE Control Systems Society (CSS) led by Tariq Samad and Anu Annaswamy, put together a large report “Impact of Control: Overview, Success Stories, and Research Challenges” (IOCT report, see http://www.ieeecss.org/main/about-the-society/ioctreport). Of course, this is not the first or the only effort in looking at future directions for control, but it does represent a substantial piece of work with input from many different people. These activities are important both for our own research community and for society more generally.
TL;DR: The Brennan torpedo was provided with a tangential flyball governor as mentioned in this paper, and it was used for coastal defense, launched from land, but it was considered less suitable than the Whitehead torpedo for use aboard ships because it was wire guided.
Abstract: Until about 1900 the word torpedo referred to a static naval mine. However, the modern mobile weapon came into being became a significant factor in naval warfare.The Brennan torpedo was deemed less suitable than the then dominant Whitehead torpedo for use aboard ships because it was wire guided, but it was accepted for coastal defense, launched from land. The trajectories of early torpedoes were haphazard, and these devices came to be controlled in bearing and depth by mechanical sensors. Initially these sensors took a wide variety of forms before the introduction of reliable gyroscopes. Gyros have dominated the field ever since, such is their utility. From a control engineering perspective it is interesting to consider the earlier contenders, which displayed great ingenuity. The Brennan torpedo was provided with a tangential flyball governor.